Samuel harris



(No Model.)

s. HARRIS. CONTACT FINGER FOR ELEGTRIG CONTROLLERS.

No. 536,803. Patented Apr. 2, 1895.

Fig!

a; a C) e x '2 a g 3 s Fig.2

WITNESSES IJV' VEN TOR J Zi UNITED STATES PATENT Orrrcn.

SAMUEL HARRIS, OF CLEVELAND, OHIO, ASSIGNOR TO THE STEEL MOTOR COMPANY,OF SAME PLACE.

CONTACT-FINGER FOR ELECTRIC CONTROLLERS.

SPECIFICATION forming part of Letters Patent No, 536,803, dated April 2,1895.

' Application filed December 5, 1894- Serial No. 530,889. (No model.)

To all whom it may concern:

Be it known that I, SAMUEL HARRIS, a citizen of the United States,residing at Cleveland, in the county ofOuyahoga and State of Ohio, haveinvented certain new and useful Improvements in Contact Fingers forElectric Controllers; and I do hereby declare the following to be afull,clear, and exact description of theinvention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to improvements in the contact fingers of electriccontrollers. Its object is to increase the efficiency and adaptabilityof the apparatus; and it consists in the novel construction, arrangementand co mbination of the parts to effect such object, as hereinafterfully described and specifically pointed out in the claims.

In the drawings Figure 1 represents in side View a contact fingerembodying my invention, shown in engagement with one of the connectingdisks of the roller of a street car controller. Fig. 2 represents thesame in plan View.

A represents the connecting disk of insulating material; a, the contactstrip embedded in its periphery.

B is an insulating disk interposed between each of the disks A, parts oftwo of which are shown in Fig. 2.

O is the contact finger, composed of the shoe or bearing piece cattachedto an endless spring 0 preferably of oval or elliptic shape and of flatmetal, which is attached at its opposite side to the carrying piece 0whereby the finger is secured to the bar D, in position to bear againstthe disk A, so as to effect the electrical connection of the circuit inthe usual way when the roller is appropriately turned by its handle.

It is well understood that the hearing be tween the bearing surface ofthe finger and the disk must be as complete as possible in order todecrease the resistance and avoid the heating of the roller andthe'inevitable burning of the contacts or other parts. For this reasonthe contact fingers are usually provided with springs to insure theirfirm contact with the disk, and various forms of coiled and fiat springsarranged in various ways have been adopted in the effort to secure thisvery desirable end. There is, however,a tendency to an unequal wear onthe shoe or contact piece of the finger, which renders it essential tothe best results thatit. should have practically universal play, yet arigidity greater than could be obtained by any joint, which would alsointroduce resistance and be objectionable on that account.

I accomplish the results aimed at by the construction above described,as the elliptical spring yields readily to pressurein any direction andalso transversely, so that the shoe 0 has suificient freedom of motionboth laterally and longitudinally and yet is kept to a firm bearing notonly throughout its length but also throughout its width. This resultcannot be obtained with coiled or flat springs, as the latter do notinsure perfect lengthwise contact of the shoe, and neither affordsperfect compensation for lateral wear.

The finger is attached to bar D by means of a connecting piece D towhichit is secured by screws 6 e, and in case of burning or greaterwearing of the shoe 0 at one end than the other, the entire finger maybe reversed by removing the screws 6 e and replacing the fingerinverted,so that thereby the life of the finger may be prolonged.

What I claim as my invention, and desire to secure by Letters Patent, is

1. A contact finger for electric controllers having the contact shoerigidly affixed to an endless spring which is free to flex in anydirection and is rigidly affixed to a carrying piece, substantially asdescribed.

2. A controller finger for electric controllers having the contact shoerigidly affixed to an endless spring of flat metal which is free to flexin any direction and is rigidly affixed to a carrying piece,substantially as described.

3. A contact finger for electric controllers having the contactshoerigidly affixed to an endless elliptical spring which is free to fiex inany direction and to which is rigidly affixed a carrying piece,substantially as described.

4. A controller finger for electric controllers having the contact-shoerigidly affixed to an endless elliptical spring of fiat metal which isfree to flex in any direction and to which is rigidly affixed acarrying-piece, substantially as described.

ICO

5. A contact finger for electric controllers having the contact-shoerigidly affixed to the long side of an elliptical spring which is freeto flex in any direction and whose free portions are without joints, andto the opposite side of which spring is rigidly affixed a carryingpiece, substantially as described.

6. A contact finger for electric controllers having the contact-shoerigidly aifixed to the long side of a flat elliptical spring which isfree to flex in any direction and whose free portions are withoutjoints, and to the opposite side of which spring is rigidly affixed a.

carrying piece, substantially asdescribedn 7. A reversible contactfinger for electric controllers having the contact-shoe rigidly aflixedto an endless spring to which is rigidly aiiixed a reversible carryingpiece, substantially as described.

8. A reversible contact-finger for electric SAMUEL HARRIS.

Witnesses:

P. PRENTISS, ROLAND RIDER.

